Aroon oscillator

//+------------------------------------------------------------------+
//|                                             Aroon oscillator.mq4 |
//|                                                           mladen |
//+------------------------------------------------------------------+
#property copyright "mladen"
#property link      "mladenfx@gmail.com"

#property indicator_separate_window
#property indicator_buffers 7
#property indicator_color1  DimGray
#property indicator_color2  Green
#property indicator_color3  Green
#property indicator_color4  FireBrick
#property indicator_color5  FireBrick
#property indicator_color6  Lime
#property indicator_color7  Red
#property indicator_levelcolor DarkSlateGray
#property indicator_width1  1
#property indicator_width2  2
#property indicator_width3  2
#property indicator_width4  2
#property indicator_width5  2
#property indicator_minimum -100
#property indicator_maximum  100


extern int    AroonPeriod      = 25;
extern int    Filter           = 50;
extern string Alerts_Settings  = "Settings for alerts";
extern bool   alerts.On        = false;
extern bool   alerts.OnCurrent = false;
extern bool   alerts.Message   = true;
extern bool   alerts.Sound     = false;
extern bool   alerts.Email     = false;


//
//
//
//
//

double buffer1[];
double buffer2[];
double buffer3[];
double buffer4[];
double buffer5[];
double buffer6[];
double buffer7[];

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
//
//
//
//
//

int init()
{
   SetIndexBuffer(0,buffer1);
   SetIndexBuffer(1,buffer2);
   SetIndexBuffer(2,buffer3);
   SetIndexBuffer(3,buffer4);
   SetIndexBuffer(4,buffer5);
   SetIndexBuffer(5,buffer6); SetIndexStyle(5,DRAW_ARROW); SetIndexArrow(5,108);
   SetIndexBuffer(6,buffer7); SetIndexStyle(6,DRAW_ARROW); SetIndexArrow(6,108);
   SetLevelValue(0, Filter);
   SetLevelValue(1,-Filter);
   
   IndicatorShortName("Aroon oscillator ("+AroonPeriod+")");
   return(0);
}

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
//
//
//
//
//

int start()
{
   int counted_bars=IndicatorCounted();
   int i,limit;
   
   if(counted_bars<0) return(-1);
   if(counted_bars>0) counted_bars--;
           limit=Bars-counted_bars;

   //
   //
   //
   //
   //
   
      if (buffer1[limit] >  50) CleanPoint(limit,buffer2,buffer3);
      if (buffer1[limit] < -50) CleanPoint(limit,buffer4,buffer5);
   
   //
   //
   //
   //
   //
   
   for(i=limit; i>=0; i--)
   {
      double AroonUp = 100.0*(AroonPeriod-iHighest(NULL,0,MODE_HIGH,AroonPeriod,i)+i)/AroonPeriod;
      double AroonDn = 100.0*(AroonPeriod- iLowest(NULL,0,MODE_LOW ,AroonPeriod,i)+i)/AroonPeriod;
         buffer1[i] = AroonUp-AroonDn;
         buffer2[i] = EMPTY_VALUE;
         buffer3[i] = EMPTY_VALUE;
         buffer4[i] = EMPTY_VALUE;
         buffer5[i] = EMPTY_VALUE;
         buffer6[i] = EMPTY_VALUE;
         buffer7[i] = EMPTY_VALUE;
                  if (buffer1[i]> Filter) PlotPoint(i,buffer2,buffer3,buffer1);
                  if (buffer1[i]<-Filter) PlotPoint(i,buffer4,buffer5,buffer1);
                  if (buffer1[i]> Filter && buffer1[i+1]< Filter) buffer6[i]= buffer1[i];
                  if (buffer1[i]<-Filter && buffer1[i+1]>-Filter) buffer7[i]= buffer1[i];
   }
   
   //
   //
   //
   //
   //
   
   if (alerts.On)
   {
      if (alerts.OnCurrent)
            int forBar = 0;
      else      forBar = 1;
      
      //
      //
      //
      //
      //

      if (buffer6[forBar]!= EMPTY_VALUE) doAlert("Arron oscillator trend chaned to UP");
      if (buffer7[forBar]!= EMPTY_VALUE) doAlert("Arron oscillator trend chaned to DOWN");
   }      
   return(0);
}


//+----------------------------------------------------------------------------------+
//|                                                                                  |
//+----------------------------------------------------------------------------------+
//
//
//
//
//

void doAlert(string doWhat)
{
   static string   previousAlert="nothing";
   static datetime previousTime;
   string message;
   
   if (previousAlert != doWhat || previousTime != Time[0]) {
       previousAlert  = doWhat;
       previousTime   = Time[0];

       //
       //
       //
       //
       //

       message =  StringConcatenate(Symbol()," at ",TimeToStr(TimeLocal(),TIME_SECONDS)," Aroon oscillator - ",doWhat);
          if (alerts.Message) Alert(message);
          if (alerts.Email)   SendMail("Arron oscillator",message);
          if (alerts.Sound)   PlaySound("alert2.wav");
   }
}


//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
//
//
//
//
//

void CleanPoint(int i,double& first[],double& second[])
{
   if ((second[i]  != EMPTY_VALUE) && (second[i+1] != EMPTY_VALUE))
        second[i+1] = EMPTY_VALUE;
   else
      if ((first[i] != EMPTY_VALUE) && (first[i+1] != EMPTY_VALUE) && (first[i+2] == EMPTY_VALUE))
          first[i+1] = EMPTY_VALUE;
}

//
//
//
//
//

void PlotPoint(int i,double& first[],double& second[],double& from[])
{
   if (first[i+1] == EMPTY_VALUE)
      {
      if (first[i+2] == EMPTY_VALUE) {
          first[i]    = from[i];
          first[i+1]  = from[i+1];
          second[i]   = EMPTY_VALUE;
         }
      else {
          second[i]   = from[i];
          second[i+1] = from[i+1];
          first[i]    = EMPTY_VALUE;
         }
      }
   else
      {
         first[i]   = from[i];
         second[i]  = EMPTY_VALUE;
      }
}